The invention relates on the one hand to a method for the gravimetric control of a mass flow from a or into a container located on a balance using an intermittent dosing pump and on the other hand to a device for the gravimetric control of a mass flow with a dosing pump which doses the material to be doesed from a or into a container located on a balance, whereby the delivery force of the dosing pump comprises pulsating components; and with a control unit which regulates the delivery force of the dosing pump on the basis of the output signal of the balance in such a manner that the average time value of the delivery force achieves a set theoretical value.
A method and a device of this type are known from the journal article "Use of a Microprocessor-Controlled Dosing Device in Biotechnology" by K. Memmert, R. Uhlendorf and C. Wandrey in Chemie-Ingenieur-Technik 59 (1987), No. 6, pp. 501-504.
A disadvantage of this known method and of this known device is that fact that for a use under sterile conditions, practically only pumps are known whose delivery flow is composed of individual delivery impulses. Hose pumps and membrane pumps are cited in the above-mentioned article as example. This pulsation is not problematic for any applications and it is sufficient to maintain the average time value at the set theoretical value. However, the pulsating component is problematic for some applications, especially in the case of very slight dosing flows, and the invention has the problem of indicating a method and a device for pulsation-free, gravimetric dosing.